Columbia

1
Columbia

• Sarah Beck

2
Review of Test Data Indicates Conservatism for
Tile Penetration

• The existing SOFI on tile test data used to
  create Crater was reviewed along with STS-87
  Southwest Research data
• Crater over predicted penetration of tile coating
  significantly
• Initial penetration to described by normal
  velocity
• Varies with volume/mass of projectile (e.g.,
  200ft/sec for 3cu. In)
• Significant energy is required for the softer
  SOFI particle to penetrate the relatively hard
  tile coating
• Test results do show that it is possible at
  sufficient mass and velocity
• Conversely, once tile is penetrated SOFI can
  cause significant damage
• Minor variations in total energy (above
  penetration level) can cause significant tile
  damage
• Flight Condition is significantly outside of test
  database
• Volume of ramp is 1920cu in vs 3 cu in for test

3
Test Overview

• Flight condition is significantly outside that of
  test database
• Actual volume of ramp is 1,920 cubic inches
  verses 3 cubic inches in the test medium.

4
Test Results

• Significant energy is required for the softer
  SOFI particle to penetrate the relatively hard
  tile coating
• It is possible at sufficient mass and velocity
• Penetration varies with volume/mass of projectile
  (e.g., 200ft/sec for 3cu. In)
• Conversely, once tile is penetrated SOFI can
  cause significant damage